<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        var r=prompt('请告诉我圆的半径');
        var r_1=parseFloat(r);
        var circumference= r_1 * 3.14 * 2;
        var area= r_1 * r_1 * 3.14;
        console.log(`圆的半径是${r_1},周长是${circumference}，面积是${area}。`);
    </script>
</head>
<body>
    1、询问用户圆的半径是多少<br>

    2、计算圆的周长和半径，并且使用console打印这两个数据如：“圆的半径是xx，周长为xx，面积为xx”

</body>
</html>